Photographic light-synchronizing mechanism



y 1941- w. A. STEENBERGEN 2, 40,813

PHOTOGRAPHIC LIGHTSYNCHRONIZING MECHANISM Filed March 31, 1939 3nventor WILLIAM A. STEENBERGEN Patented May 6, 1941 I UNITED STATES PATENT OFFICE PHOTOGRAPHIC LIGHT-SYNCHRONIZIN G MECHANISM 1 Claim.

My present invention relates to a photographic light-synchronizing mechanism for use with cameras whereby ignition of the flash element of a conventional flash bulb is timed to coincide with the exposure of photo-sensitive papers or plates by means of the movement of a shutter.

It is well known that synchronizing means for flash bulbs arranged to coincide with the operation of a shutter of a camera have been of a relatively complicated and intricate nature, and consequently very expensive. The inherent complexity of the present devices has required the services of experts or specialists for the adaptation of the devices to the cameras and their proper adjustment. Further, the complex nature of the current devices renders them susceptible to disadjustment from very slight shocks and often during ordinary handling.

It is, therefore,a primary object of my invention to provide a simple and efiicient mechanism ior igniting photographic flash bulbs and simultaneously operating the shutter which can be readily adjusted and synchronized by persons of little experience.

A further object of my invention has been the provision of a synchronizing mechanism that can be adapted to various cameras and adjusted to the conditions to be met with a minimum of difilculty.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawing, forming a part of this specification, and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a view in perspective of the device of my invention showing attached thereto the standard cable release of the regulation camera;

Figure 2 is a vertical cross sectional view taken through the upper portion of my device and detailing the construction and operation thereof;

Figure 3 is a view through the adjustment feature of my device showing installed therein the standard plunger of a camera cable release,

Figure 4 is a plan view of the push-through switch mechanism employed in connection with my invention, and

Figure 5 is a plan view of the spacer insulation disc and the contact member carried thereby.

Referring to Figure 1 a battery case I provided with the usual screw cap 2 has secured to its upper end a socket 3 of conventional construction. A bracket arm 4 having an upturned portion 5 is attached to .the side of the case- I by Cil means of rivets 6, 6. A series of threaded holes I, 1 are adapted to be engaged by an attaching thumb screw 8 through the cooperation of the threaded boss 9. A flash bulb or lamp I0 is shown threaded or otherwise secured in the socket 3 and a reflector l I is adjustably supported behind the bulb ill by means of the reflector arm. [2. The reflector arm i2 has a slotted opening l3 which engages over a bolt Hi on which is threaded the thumb screw I5, to provide adjustment of the reflector according to the size of the lamp. Rivets i6, i6 rigidly secure the reflector to the arm i2. Within the interior of the battery case I, as may best be seen in Figure 2, I have shown a portion of a pair of dry cell batteries l1, ll of the conventional type. A contact l8 engages the core of the uppermost battery and a lead wire I9 is provided and attached to one pole of the lamp socket switch as will later be described. The contact I8 is insulated from the battery casing. A ground wire 20 is secured at 2| to the casing and it will be understood that the negative side of the dry cell batteries is grounded to the casing. A switch receptacle 22 is fitted within the socket 3 and is provided with an interior slidable yoke 23 having aligned, threaded extensions 24, 24'. A spring 25 cooperates with the yoke and a toggle circuit closer 26 to make and break contacts to open and close the circuit.

A presser button 21 is secured to one of the threaded extensions 24, passing through a slot 28 in the casing 3 and extends exterior of the casing. A similar presser button 21 is attached to the other extension 24' in the customary manner extending exteriorly of the socket 3 and into the interiorly threaded collar 29. The collar 29 is securely attached to one side of the socket 3 and extends outwardly therefrom.

The yoke 23 and the buttons 21, 21' are slidably operable in the receptacle 22 through the transverse slot 50, which is widened in its central portion to provide space for the toggle circuit closer 26. Suitable depressions in either side of the receptacle communicate with the enlarged area, and contact members 5| and 52 are fitted therein with their free ends so arranged that when the toggle circuit closer is caused to assume the position shown in Figures 2 and 4, it edges engage the contact members 5| and 52 and close the circuit.

The wire it attaches to a binding post (not shown) which is in communication with the member 5|. An insulation disc 53 covers the upper face of the receptacle 22 and has a slot It for the receptacle of the offset arm 55. The arm IS passes through the slot II and on one end has the contact button I, which when the disc is properly positioned in the casing is located in the central bottom: portion of the bulb socket, as shown in Figure 2. That portion of the offset arm 55 which is under the disc 53 has an angular extension I! that contacts the wins 1 of the contact member '2.

The socket casing 8 is provided with the usual insulating tube 30 and the interior socket contact m als 1 and the threaded bushing or ferrule I1 is back threaded to receive the screw base 02 of the I lamp II. The contact "in the base of the lamp frictionally engages the button contactor I4 and it will be understood that the socket contact Ii and the button contactor 34 are suitably connected to the lead wires II and II when the switch is in the closed position, substantially as indicated inFigure2. Thesocketll is'groundedtothe casing lthrough thewire II. c

When current is applied to the base I! and the contact 33 an igniting glow is produced in .a fusible strip member which is across the points I! and Il and which ignites'a flash material 31' that may be formed of magnesium fllament or magnesium foil and the bulb lights, producing a very bright flash.

Referring now to Figure 3, the interiorly threaded collar It is shown as having engaged therewith a threaded bushing 81 having its outer terminal end forming a ferrule seat and a lock screw 3! securely flxes'the bushing in adjusted and set relation to the collar 2!. A cap nut 39 is threaded on the outer end of the bushing 31 and has a hole ll in its closed end. A standard camera cable release comprising a cable sheath II and a camera attaching plug 42 has in its interior a plunger cable 48 to which a plunger 44 is attached at the end adjacent the plug 42. The opposite end of the cable is secured in as conventional manner to a spring-pressed plunger rod II which passes through a cable ferrule ll anda plunger button 41 at the outer end of the rod I. is customarily provided for a photographer to press in opening and closing the shutter.

When it is desired to attach the device to a camera the thumb screw 8 is engaged by the one of the holes 1 which most closely coincides with the tripod socket on the body of the camera. As the thumb screw I is screwed up and through the attached arm 4 it reaches a point whereit can freely turn and then may engage the threads of the socket in the camera and tighten the camera to the attaching arm.

The camera attaching plug 42 on the cable is fitted into the hole provided therefor in the usual camera and screwed up tight. The cap but a which, has previously been slipped over the cable is brought into engagement with the threads on the end -of the ferrule 31. plunger rod I and button 41 fit inside the ferrule in the path of the element 21. that would be in the on position and the ferrule 4. seats,

on the end of bushing 31 and is retained thereon by cap 8!.

the collar 2! are securely locked in the adjusted depress the said plunger button.

. bushing and having an opening for the reception Previous to the insertion of the plunger rod inside the ferrule the set screw as is loosened wardly threaded out of the collar II to its approximate limit. With the button 21' in the "on position the bushing 81 is turned in its threads until the plunger button 41 contacts the button 21' sufliciently to activate the shutter through the operation of the plunger cable I. A few trial operations by withdrawing and again pressing the buttons 21 and II will indicate whether or not the shutter is being operated all of the time. v

As desired, l the ferrule J1 may, be further screwed into the collar 2! until just the proper action is obtained. When the proper adjustment has been made the set screw II is tightened against the bushing 31 and the bushing 31 and position.

It is to be understood that the form of my invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of my. invention, or the scope of the subjoined claim.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

In a photographic flashlight device wherein a battery casing having batteries therein is asscciated with a bulb socket supporting a flash bulb; the combination of an encased pushthrough switch mechanism electrically in circ'uit associated with said battery casing and batteries and said bulb" socket and a flash bulb therein and operable to close the normally open circuit to thereby light said flash bulb, said pushthropghswitch mechanism having a-pair of diametrically protruding push-buttons one of which when manually pressed operates the switch mechanism to close the electrical circuit and simultaneously causes the other push-button to protrude a greater distance from the enclosing casing than when the switch is open, a collar on the switch casing and encircling the pushbutton thereof which is caused to protrude a greater distance upon theeclosing of the switch. a bushing engaged in said collar and having a length sumcient to receive the plunger rod of the shutter release cable and also to form a seat on its outer end for the flanged cable ferrule of-sfld mechanism, and a cap on the outer end of said of the shank of the cable ferrule of a cable shutter release mechanism to thereby position and retain the ferrule in' its seat on said bushing and to position the spring urged plunger button of the shutter release mechanism so that the greater protrusion of the adjacent push-button will WILLIAM A. STEENBERGEN. 

